Artificial limb



c. DESO U' TTER ARTIFICIAL LIMB Filed May 8. 1923 Patented May 13, 1924.

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r-Arnur CHARLES DESOUTTER, 'OF LONDON, ENGLAND, ASSIGNOR 'IO DESOUTTEB BROTHERS LIMITED, OF LONDON, ENGLAND, A BRITISH COMPANY.

ARTIFICIAL LI-MB.

Application filed May 8,

To all whom it may concern.

Be it known that I, CHARLES DESOUTTER, a subject of the King of Great Britain, residing at 73 Baker Street, London, W. 1, England, have invented certain new and useful Improvements in or Relating to Artificial 'Limbs, of which the following is a specification. p

This invention relates to improvements in and connected with artificial limbs, and relates more particularly though -not exclu sively to improvements connected with the knee joints of artificial legs.

As is well known in connection with art-ificial legs, it is usual to provide the knee joint with a check cord, consisting of a ring or loop of suitable flexible material which is connected on the one hand to a stud or the like or attached by means of a strap at the back of thebucket or upper leg portion, and on the other hand to the lower leg portion, the check cord being mounted to prevent the flexing of the knee joint beyond its fully extended position. It is found in practice that this check cord is subjected to a comparatively heavy tension, and it very often happens that the cord is soon worn out or partially cut through or the members of the upper and lower leg portions to which it is connected become damaged due to the heavy strain.

The object of the present invention consists in a construction in which the major portion of the strain on the check cord is distributed on to the upper leg portion or bucket itself, and in which the points of attachment of the check cord to the upper and lower portions of the limbs are subjected to less wear than hitherto.

According to the invention, the upper or bucket portion of the leg and also if desired the lower portion of the leg are provided with projecting surfaces over or around which the check cord passes, and I prefer to provide the material of the leg with grooves or recesses in which the check cord is partly housed, a suitable cover plate or securing member being employed which not only maintains the check cord in proper engagement with the projecting surface of the leg, but exercises a wedging action to a certain extent which reduces the friction between the check cord and the leg to a minimum.

In order that the invention may be readily understood reference is made to the ac- 1'923. Serial No. 637,411.

companying drawings, which show the invention applied to a knee joint of an artilicial leg by way of example. In the draw- 1ngs:

i Fig. 1 is a View of the knee joint showing the same partly in section, the lower leg portion being indicated by dotted lines.

Fig. 2 is a rear view of the bucket or upper leg portion seen from the right of Fig. 1.

In the drawings, the knee cap portion 10 only of the upper leg portion or bucket is shown, it being understood that the upper leg portion is attached to the knee cap in the usual manner, the rivet or bolt holes for such attachment being indicated at 11.

The knee cap portion 10 is provided with a cylindrical tubular housing 12 for the kneebolt and the lower surface of the knee cap is curved to enable the two portions of the artificial leg to bend about the axis of the knee bolt. 3

At the back of the knee cap 10 is provided a projecting member 13, preferably formed by pressing, rolling or working up the metal of which the knee cap is formed so as to produce an upstanding boss or hump, the inner side of which is reinforced by a block 14, which is riveted to the boss 13, and afterwards screw threaded to receive a securing screw for a cover plate 15, hereinafter referred to.

The walls of the boss 13 are curved to correspond more or less to the curvature of the check cord indicated by dotted lines at 16, and I prefer to provide the outer surface of the knee cap portion with grooves or channels 17, 17, which extend downward- 1y from the sides of the boss 13 towards the bottom of the knee cap, so that the cord 16, may be partly housed therein, the grooves or channels 17, 17, forming a continuation of and being disposed at a tangent to the circular grooved portion 18 extending partly round the boss 13, on its upper side.

The cover plate or securing member 15 is of substantially triangular shape as shown in Fig. 2, the lower portion of the plate being provided with an apertured flat portion 19 which abuts against the outer flat face of the boss 13, through which passes a screw 21, and this aperture is partly surrounded on its upper side by a concentric groove or channel located on the inside of the plate, so as to register with the grooved portion 18 surrounding theboss 13. By this means the check cord is covered in at the portion thereof, which lies within the groove 18. The cover plate is secured to the back of the knee cap 10 by screws 20, each of which engage screw threaded holes in the knee cap portion, and for greater strength the inner side of the knee cap is reinforced by riveting thereto blocks 22, in which the screw threaded holes for the screws 20 are formed. The cover plate when screwed into position firmly retains the check cord in the groove 18 surrounding the boss or projecting portion 13, and the major portion of the strain on the check cord is taken up by the projecting boss, so that no heavy strains are transmitted to the screw 21. The cover plate furthermore may exert sufficient pressure on the check cord to effect a wedging action on the latter thereby reducing the friction between it and the leg to a minimum.

The provision of the groove or channel 18 surrounding the boss 13 and the groove 17 17, tangentially disposed thereto is not absolutely necessary and they can be eliminated if so desired.

The opposite end of the looped check cord may be secured to the lower leg portion either on the outside or on the inside thereof in a similar manner, as will be readily un derstood.

The invention may also be applied to the joint between the foot portion and the lower leg portion, or between the upper and fore arm of an. artificial arm or in any other cases where a check cord is employed.

lVh-at I claim as my invention and desire to secure by Letters Patent in United States of America is 1. In an artificial limb comprising pivotally connected sections, one of said sections being formed of metal, said metal section formed with a boss and a groove, a check cord adapted to pass over said boss and seat in said groove, a cover plate secured to said metal section grooved upon its inner side to enclose the cord, the said grooves forming together a substantially circular channel for said check cord.

2. In an artificial limb comprising sections pivotally connected together, one of said sections being formed of metal, said metal section being formed with an are shaped transverse groove and vertically extending grooves communicating therewith, a centrally disposed boss extending upwardly between said vertical grooves and partially enclosed by said vertical and are shaped grooves, a check cord adapted to seat in said grooves and pass around said boss, and a cover plate secured to said metal section having an are shaped groove corre sponding in size and contour to the are shaped groove in said metal section, said last two mentioned grooves forming a substantially circular channel for said check cord.

In witness whereof I affix my signature.

CHARLES DESOUTTER. 

